James argues that it is good to believe in God but it’s not enough as the demons also believe, and shudder. (James 2:19) They tremble in fear of the certainty of their condemnation and so should we. This is what Felix felt when Paul preached about righteousness, self-control, and the judgment to come. (Acts 24:24-25) Knowing the terror of the Lord we should persuade men (2 Cor. 5:11).